Which factors need to be controlled to ensure repeatability during testing?

Ensuring repeatability during testing is crucial for obtaining reliable and consistent results. To achieve this, various factors should be controlled, as they can significantly influence the outcomes of vibration analysis.

Controlling test load, sensor mounting, and test configuration is essential for repeatability. The test load affects the operational dynamics of the system being tested. Variations in load can lead to different resonance frequencies and amplitude responses, thereby impacting the results.

Sensor mounting is equally critical; improper or inconsistent mounting can introduce variations in the readings. If a sensor is not securely attached or positioned differently across tests, the data collected may reflect these differences rather than the true behavior of the system.

Lastly, test configuration encompasses the overall setup, including the arrangement of equipment, connection methods, and measurement parameters. Any inconsistencies in how the tests are set up can lead to varying results, which complicates the analysis and interpretation of data.

In contrast, the other options focus on a limited scope that does not encompass the multiple dimensions necessary to ensure consistent and reliable testing. Therefore, controlling test load, sensor mounting, and test configuration is the most comprehensive approach to ensuring repeatability in vibration testing.